Jewelry clasp

ABSTRACT

The jewelry clasp includes first and second parts, magnetic means for coupling the parts and mechanical means for coupling the parts. The mechanical coupling means takes the form of first and second interengaging screw threads. The first part includes a recess defined by an internal surface having the first interengaging screw threads. The second part has an external surface carrying the second interengaging screw threads

CROSS-REFERENCE TO RELATED APPLICATIONS

Not Applicable

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

REFERENCE TO A “SEQUENCE LISTING”, A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON COMPACT DISC

Not Applicable

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to clasps for jewelry and more particularly to a safety clasp that includes magnet coupling means and mechanical coupling means in the form of interengaging screw threads.

2. Description of Prior Art Including Information Disclosed Under 37 CFR 1.97 and 1.98

Clasps for jewelry such as bracelets and necklaces are well known in the art. Many clasps have a single coupling means, which, if accidentally disengaged, results in the jewelry falling off the wearer and possibly being lost. Since jewelry often has high monetary and/or sentimental value, the possibility of lost due to the accidental opening of the clasp is to be avoided.

Accordingly, it is known to utilize as second coupling means, in conjunction with the first coupling means, so as to substantially reduce the possibility that the clasp will accidentally disengage. For example, it is known to use a magnetic coupling means and a mechanical coupling means, such as is disclosed in U.S. Pat. No. 5,349,725 to Levy and U.S. Pat. No. 5,197,168 to Levy, where the magnetic coupling draws the parts of the clasp together and a plate-like mechanical closure member, attached to the exterior of one of the parts, engages a complementarily shaped portion on the exterior of the other part. However, because those clasps have the mechanical closure members that are externally mounted, those members may detract from the appearance of the clasp. Further, such a member may catch on the clothing or skin of the wearer.

To avoid the problems inherent in the use of an external mechanical closure member, it is known to use an internal mechanical coupling means in conjunction with the magnetic coupling means, as disclosed in U.S. Pat. No. 4,231,137 to Fujimoto and U.S. Pat. No. 3,129,477 to Mizuno. The clasps disclosed in the Fujimoto and Mizuno patents utilize a mechanical coupling means in the form of a “bayonet-type” closure, where a portion of one part is inserted into a recess in the other part and then rotated. However, the bayonet-type of mechanical coupling does not provide the safety necessary for many jewelry applications.

It is, therefore, a prime object of the present invention to provide a jewelry clasp with a mechanical coupling means that, when used in conjunction with magnetic coupling means provides a high degree of protection against accidental disengagement of the clasp parts.

It is another object of the present invention to provide a jewelry clasp with a screw-type mechanical coupling means.

It is another object of the present invention to provide a jewelry clasp with a screw-type mechanical coupling means including interengaging screw threads.

It is another object of the present invention to provide a jewelry clasp having an aesthetically pleasing appearance.

It is another object of the present invention to provide a jewelry clasp with a screw-type mechanical coupling means formed of a small number of relatively inexpensive and easily assembled parts that cooperate to provide a long useful life.

BRIEF SUMMARY OF THE INVENTION

In accordance with one aspect of the present invention, a jewelry clasp is provided including first and second parts. The parts may be attached by magnetic coupling means and mechanical coupling means. The mechanical coupling means include first and second interengaging screw threads.

The first part includes a recess defined by an internal surface. The internal surface has the first interengaging screw threads thereon. The second part includes an external surface. The external surface has the second interengaging screw threads thereon.

One of the first and second parts is at least partially received within the other of the first and second parts.

The clasp is designed for use with jewelry having first and second ends. It includes means for connecting the first part to the first end of the jewelry and means for connecting the second part to the second end of the jewelry.

The first part includes first and second portions. The first portion of the first part has a substantially tubular shape. The second portion of the first part has a substantially cylindrical shape. The second portion of the first part is received within the first portion of the first part. Preferably, the second portion of the first part is movably received within the first portion of the first part.

The magnetic coupling means includes magnet means associated with the first portion of the first part and the second part.

The second portion of the first part is rotatably and axially movably received with the first portion of the first part.

In accordance with another aspect of the present invention, jewelry is provided having first and second ends. The jewelry has a clasp including first and second parts. The first part is attached to the first end. The second part is attached to the second end. Magnetic means are provided for coupling the first and the second parts means. Mechanical means are provided for coupling the first and the second parts. The mechanical coupling means includes first and second interengaging screw threads.

The first part includes a recess defined by an internal surface. The internal surface has the first interengaging screw threads thereon. The second part includes an external surface. The external surface has the second interengaging screw threads thereon.

One of the first and second parts is at least partially received within the other of the first and second parts.

Means are provided for connecting the first part to the first end of the jewelry. Means are also provided for connecting the second part to the second end of the jewelry.

The first part includes first and second portions. The first portion of the first part has a substantially tubular shape. The second portion of the first part has a substantially cylindrical shape. The second portion of the first part is received within the first portion of the first part. Preferably, the second portion of the first part is movably received within the first portion of the first part.

The magnetic coupling means includes magnet means associated with the first portion of the first part and the second part.

The second portion of the first part is rotatably and axially movably received with the first portion of the first part.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF DRAWINGS

To these and to such other objects that may hereinafter appears, the present invention relates to a jewelry clasp as described in detail in the following specification and recited in the annexed claims, taken together with the accompanying drawings, in which like numerals refer to like parts and in which:

FIG. 1 is an environmental view showing a bracelet with the clasp of the present invention on the wrist of a wearer;

FIG. 2 is an enlarged isometric view of the clasp in the engaged state;

FIG. 3 is a view similar to FIG. 2 but showing the clasp in the disengaged state;

FIG. 4 is an exploded isometric view of one of the clasp parts;

FIG. 5 is an exploded isometric view of the other of the clasp parts;

FIG. 6 is a cross-sectional view of the clasp with the parts in the engaged state;

FIG. 7 is a view similar to FIG. 6 showing the magnetic coupling means engaged and the mechanical coupling means disengaged; and

FIG. 8 is a view similar to FIG. 6 showing the clasp parts in the disengaged state.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1 and 2 show the clasp of the present invention, generally designated A, as it would appear connected to an article of jewelry, such as a bracelet 10. The clasp has two main parts, 12 and 14. Each of the parts 12, 14 includes a means for connecting that part to a different end 16, 18 of bracelet 10. As shown, each of the connecting means includes an axially extending stem 20, 22, protruding from parts 12, 14, respectively.

Attached to the end of each stem 20, 22 is a fixed ring 24, 26, respectively. A movable ring 28, 30 is permanently attached to each of the fixed rings 24, 26, respectively. A conventional spring-loaded hook-type connector 32 is attached to end 16 of bracelet 10 so as to removably engage ring 28. A similar connector 34 extends from ring 30 and is adapted to engage ring 36 on the end 18 of bracelet 10.

The parts of clasp A are illustrated in FIGS. 3, 4 and 5. Part 12 of the clasp includes a tubular member 38. Member 38 has a bore with an internal surface 40 having internal screw threads 42. Member 38 is freely received over and axially movable a limited distance relative to a substantially cylindrical inner magnet member 44, which forms the other element of part 12. Part 44 has a hemispherical end, from which stem 20 extends, and a planar end.

However, member 38 cannot move off member 44 in either direction. It cannot move towards the right, as seen in FIGS. 6, 7 and 8, because ring 28 is larger than the inner diameter of the bore of member 38. It cannot move towards the left, as seen in those figures, due to an inwardly extending stop member 46 proximate the non-threaded end (left as seen in the figures) of member 38, through which magnet member 44 cannot pass.

The other part 14 of clasp A is a second magnetic member with external screw threads 48. Part 14 has a hemispherical end (right, as seen in the figures) from which stem 22 extends and a planar end (left, as seen in the figures) that faces the planar end of member 44. The exterior surface of part 14 has screw threads 48. Those screw threads are designed to engage the internal screw threads 42 on member 38 when member 38 is rotated relative to part 14.

In order to close the clasp, part 14 is magnetically attracted to member 44 to draw parts 12 and 14 toward each other, with the planar surfaces of member 44 and part 14 facing each other, as shown in FIG. 8. When member 44 is adjacent part 14, as shown in FIG. 7, tubular member 38 is moved toward part 14, such that internal screw threads 42 of member 38 begin to engage exterior screw threads 48 on part 14. Tubular member 38 is then rotated clockwise relative to part 14 to completely interengage the screw threads. When the screw threads are completely engaged, the clasp is closed and appears as shown in FIG. 6.

To disengage the clasp, the opposite operations are preformed. Tubular part 38 is rotated counter-clockwise relative to part 14 until the screw threads are disengaged. Then member 38 is moved along member 44, away from part 14, and member 44 is pulled apart from part 14 with a force sufficient to overcome the magnetic attraction between member 44 and part 14.

It will now be appreciated that the present invention relates to a jewelry clasp that includes first and second parts, magnetic coupling means and mechanical coupling means. The mechanical coupling means takes the form of first and second interengaging screw threads. The first part includes a recess defined by an internal surface having the first interengaging screw threads. The second part has an external surface carrying the second interengaging screw threads

While only a single preferred embodiment of the present invention has been disclosed for purposes of illustration, it is obvious that many modifications and variations could be made thereto. It is intended to cover all of those modifications and variations which fall within the scope of the present invention, as defined by the following claims. 

1. A jewelry clasp comprising first and second parts, magnetic coupling means and mechanical coupling means, said mechanical coupling means comprising first and second interengaging screw threads.
 2. The clasp of claim 1 wherein said first part comprises a recess defined by an internal surface having said first interengaging screw threads and said second part comprises an external surface having said second interengaging screw threads.
 3. The clasp of claim 1 wherein and of said first and second parts is at least partially received within the other of said first and second parts.
 4. The clasp of claim 1 for use with jewelry having first and second ends, further comprising means for connecting said first part to said first end of the jewelry and means for connecting said second part to said second end of the jewelry.
 5. The clasp of claim 1 wherein said first part comprises first and second portions.
 6. The clasp of claim 5 wherein said first portion of said first part has a substantially tubular shape.
 7. The clasp of claim 5 wherein said second portion of said first part has a substantially cylindrical shape.
 8. The clasp of claim 6 wherein said first portion of said first part has a substantially tubular shape.
 9. The clasp of claim 8 wherein said second portion of said first part is received within said first portion of said first part.
 10. The clasp of claim 8 wherein said second portion of said first part is movably received within said first portion of said first part.
 11. The clasp of claim 5 wherein said magnetic coupling means comprises magnet means associated with one of said first portion of said first part and said second part.
 12. The clasp of claim 5 wherein said magnetic coupling means comprises magnet means associated with said first portion of said first part and said second part.
 13. The clasp of claim 8 wherein said second portion of said first part is rotatably and axially movably received with said first portion of said first part.
 14. Jewelry having first and second ends including clasp comprising first and second parts, said first part being attached to the first end and said second part being attached to the second end, magnetic means for coupling said first and said second parts means and mechanical means for coupling said first and said second parts, said mechanical coupling means comprising first and second interengaging screw threads.
 15. The jewelry of claim 14 wherein said first part comprises a recess defined by an internal surface having said first interengaging screw threads and said second part comprises an external surface having said second interengaging screw threads.
 16. The jewelry of claim 14 wherein and of said first and second parts is at least partially received within the other of sad first and second parts.
 17. The jewelry of claim 14 comprising means for connecting said first part to said first end of the jewelry and means for connecting said second part to said second end of the jewelry.
 18. The jewelry of claim 14 wherein said first part comprises first and second portions.
 19. The jewelry of claim 14 wherein said first portion of said first part has a substantially tubular shape.
 20. The jewelry of claim 19 wherein said second portion of said first part has a substantially cylindrical shape.
 21. The jewelry of claim 20 wherein said first portion of said first part has a substantially tubular shape.
 22. The jewelry of claim 20 wherein said second portion of said first part is received within said first portion of said first part.
 23. The jewelry of claim 21 wherein said second portion of said first part is movably received within said first portion of said first part.
 24. The jewelry of claim 18 wherein said magnetic coupling means comprises magnet means associated with one of said first portion of said first part and said second part.
 25. The jewelry of claim 18 wherein said magnetic coupling means comprises magnet means associated with said first portion of said first part and said second part.
 26. The jewelry of claim 21 wherein said second portion of said first part is rotatably and axially movably received with said first portion of said first part. 